Wastegate Bypass Regulator Valve, Checking

Wastegate Bypass Regulator Valve, Checking

Special tools, testers and auxiliary items required
- Multimeter
- Wiring diagram.

Test requirements
- Fuse S345 OK.
- The Engine Component Power Supply Relay J757 OK.
- The ignition switched off.

NOTE: Voltage for the Wastegate Bypass Regulator Valve N75 is supplied by the Engine Component Power Supply Relay J757.

Test procedure
- Perform a preliminary check to verify the customers complaint. General Diagnosis

Start diagnosis







- Remove engine cover - arrows -.

Checking internal resistance







- Disconnect electrical harness connector - 2 - at Wastegate Bypass Regulator Valve N75.







- Using the Multimeter V.A.G 1526 A or equivalent, check the Wastegate Bypass Regulator Valve N75 for resistance.

Specified value: 20 to 25 Ohms (at approx. 20 degrees C).

If the specification is not obtained:
- Replace the Wastegate Bypass Regulator Valve N75.

If the specification was obtained:

Checking Voltage supply







- Using a multimeter , check the Wastegate Bypass Regulator Valve N75 electrical harness connector terminal 1 to Ground (GND) for voltage.

Wastegate Bypass Regulator Measure to
Valve N75 electrical harness
connector terminal
1 Engine Ground (GND)

- Operate the starter briefly.

Specified value: battery voltage.

- Switch the ignition off.

If the specified value was not obtained:
- Check the Wastegate Bypass Regulator Valve N75 electrical harness connector terminal 1 to the Engine Component Power Supply Relay J757 socket 2/87 for an open circuit, short circuit to each other, Battery (+), or Ground (GND).
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the wiring connection.

If no malfunctions are found in the wiring:

Checking wiring

If the manufacturers test box is being used. Perform the following step.
- Install the test box.

If the manufacturers test box is not being used. Perform the following step.
- Remove the Engine Control Module (ECM) J623.







- Using a multimeter , check the Wastegate Bypass Regulator Valve N75 electrical harness connector terminal 2 to Engine Control Module (ECM) J623 electrical harness connector T60 terminal 21 for resistance.

Wastegate Bypass Regulator Engine Control Module (ECM)
Valve N75 electrical harness J623 electrical connector T60 terminal
connector terminal or test box socket
2 21

Specified value: 1.5 Ohms max.

If the specification is not obtained:
- Check the wiring for a open circuit, short circuit to each other, Battery (+), or Ground (GND).
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring and if the voltage supply was OK:
- Erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
- Perform a road test to verify repair.

If the DTC does not return:
Repair complete, Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

- End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:
- Replace the Engine Control Module (ECM) J623.
- Assembly is performed in the reverse of the removal.

Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
1. Check the DTC memory. Diagnostic Mode 03 - Read DTC Memory
2. If necessary, erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
3. If the DTC memory was erased, generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

End of diagnosis